


here to serve

by shotacatboy



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Explicit Sexual Content, M/M, Male My Unit | Byleth, Praise Kink, Pre-Time Skip, Teacher-Student Relationship, dimitri in a maid dress, thigh fucking
Language: English
Status: Completed
Published: 2020-07-04
Updated: 2020-07-04
Packaged: 2021-03-05 01:40:07
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,346
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25056325
Author URL: https://archiveofourown.org/users/shotacatboy/pseuds/shotacatboy
Summary: "Well," Byleth says, "I cannot so much as consider a moment when you have beenunattractive.This, however…," he mutters, appreciatively running his hands over Dimitri's sides, "is especially tantalizing. And as much as I love this dress, I want nothing more than to ruin it."Dimiri says nothing. Byleth's lips curl into a smirk."Will you allow me to?"Dimitri squirms under Byleth's close scrutiny. When he answers, his tone is soft, shy."Please."
Relationships: Dimitri Alexandre Blaiddyd/My Unit | Byleth
Comments: 4
Kudos: 86





	here to serve

**Author's Note:**

> this fic is a commission for a friend of mine!! i also love the idea of dimitri in a maid dress so this was tons of fun to write haha
> 
> hope u enjoy!!!

Dimitri is beautiful in a way that's impossible not to be aware of, Byleth thinks.

There is something so utterly  _ captivating  _ about him that Byleth cannot quite place his finger on, something primal but gorgeous, intimidating but attention-grabbing. Whether they are across the battlefield or inside the classroom, Byleth is unable to help the way his eyes flutter towards the prince, catching his gaze and then releasing as he refocuses his attention towards his duties.

And, certainly, in the countless weeks thus far he's spent silently observing Dimitri, he is not one to miss the fleeting glances Dimitri sends him in return, or the faint blushes that dust his cheeks during those special, private moments when they are able to share tea together.

(Sometimes, as he happens across the latter, Byleth must resist the urge to reach across the table and plant a gloved hand upon Dimitri's cheek, lest the gesture come across as anything less than appropriate. He is aware that, in his role as a professor, such selfish indulgences with a student are not exactly viewed highly of.)

There are also the times when Byleth suffers injuries after a squirmish, when the dust settles and Dimitri runs up to him, fretting over his wounds and calling for a nearby mage. When Byleth observes him in these moments he sees the relief in his eyes that he is safe, but underlying fear and paranoia all the same—fear, perhaps, that he might one day lose something he values dearly.

It is the way of fighting, Byleth realizes. Of war. Life is a fickle thing, a lesson he has more or less known since he was a child. When he was a mercenary there were always required precautions in his missions, and the threat that one unlucky thrust of his sword may very well cause his breath to be snuffed out in an instant.

The world, he's aware, is cruel. And unfair. Yet, as he notes the tears stinging Dimitri's eyes after a fight, and how he wails over the senseless loss of innocent lives, this is a reality one quite so gentle and beautiful as him will never be fully able to accept.

It is why, one night, when a near soundless knock lands on his office door and he opens it to see the student in question, he shoves his inhibitions aside. There is talking, and crying, and eventually the soft press of Dimitri's lips against his own.

Then, soon after, a different sort of crying, as Dimitri is planted atop Byleth's desk and Byleth slowly pushes his length into him, listening intently as Dimitri quivers beneath him.

"Professor," he chants, quickly turning the word into a desperate mantra. "Professor,  _ please." _

He does not elaborate on what he wants, but he doesn't need to. Byleth complies, and smiles when Dimitri spills between them.

He decides, henceforth, that he would not mind this becoming a regular occurence.

***

As per Byleth's request—and Dimitri's eager compliance—their trysts continue for some months. Due to their infrequency on account of both of their busy schedules, the nights they spend in Byleth's quarters are near distracting to think about whenever they are in professional settings.

The longing glances Dimitri grants him certainly do not help this fact.

Today especially. Dimitri gnaws on his lower lip as he stares at Byleth from across the classroom, brows furrowed in a way that has Byleth almost snapping his quill in half at the sight alone.

_ Tonight,  _ he tells himself. He turns his back to Dimitri and glares rather impatiently at his tactics primer.  _ You can hold off until tonight. _

"Professor?"

He snaps his gaze upright. Annette startles, clearly not expecting such a hostile reaction. She holds out the book she'd had tucked under her arm uncertainly.

"I, uh! I-if you could assist me with this spell… I've been having some trouble casting it properly…"

Byleth nods, smiles. He pretends he cannot see Dimitri watching him out of his peripheral. "Yes," he says, "of course."

Even so, for the remainder of the day his mind continuously wanders. To Dimitri, and what he might be plotting if he's been behaving this bravely.

The possibilities are thrilling to consider, and as he sits through another slow meeting with Hanneman and Manuela he drums his fingers antsily against his lap.

***

Expectedly, he finds out that evening. The awaited knock at his door has him practically tripping over his feet as he rushes to answer it, turning the knob and—

A tug. The door slams shut. Byleth hears a nervous whimper from the other side, where Dimitri is presumably holding it closed.

"Dimitri," Byleth calls. "What's wrong? You seemed so eager earlier."

There is a long pause, then, "I changed my mind. This was a terrible idea."

Now Byleth is intrigued. He attempts tugging on the knob again, to no avail. Dimitri's physical strength is far greater than his. "What was?"

"N-nothing," Dimitri stammers, voice breaking. "I-if I may. I will be returning to my quarters…"

The hand holding the door closed slackens. Byleth, seizing the opportunity, yanks it open and immediately freezes at the sight that greets him.

_ Oh. _

Immediate arousal pools in Byleth's stomach, and he opens and closes his mouth again, grasping for the right words. He cannot peel his eyes from Dimitri's form, not even for a second.

Still, he sputters. "Ah, so you are… A dress," he finishes, stupidly.

Dimitri blushes a deep red and tugs at the black silk, attempting to tug the skirt of the garment down over his exposed thighs.  _ Too late,  _ Byleth thinks, staring openly. Lustfully.

It is nothing more than a simple black-and-white afternoon dress, but Byleth is inexorably fixated on it all the same. The fabric is thin, light, graciously hugging the leanness of Dimitri's muscles and puffing out around the waist, stopping several inches above his knees. Blue lace, as well, is tied in a ribbon at his collarbone, matching the highlights at the cuffs of its sleeves.

Form-fitting, but not too tight. Byleth glances downward and sees that even the heels on Dimitri's feet appear to be the perfect size.

He brings his eyes to Dimitri's once more, brow raised in a silent question.

He shakes his head, however, anxiously wringing his hands together. He lowers his head and asks, "M-may I come in? Before someone sees…"

Byleth nods and allows him entrance. Then, once the door is closed and locked behind them, Byleth is on him in an instant, shoving him against the wood and planting a curious hand on his thigh. Dimitri shudders as the leather dips into his skin.

Byleth gently pats Dimitri's head with his other hand. Calloused fingers curl through golden locks, and he says, "Tell me."

Dimitri struggles to speak. Byleth pretends he doesn't notice, slowly snaking his rovering hand upward while Dimitri lets out a needy whine.

"I-It was… I… It w-wasn't my idea," he gasps, as Byleth's teeth graze his ear. "M-Mercedes, she… she needed a subject for her sewing, and—"

Byleth gropes him. He groans out lowly, then slaps a palm over his mouth.

"And you decided you would seduce me in this?" asks Byleth, bemused. He resists the urge to smile.

"Is that not so?" he presses, when Dimitri does not respond right away. "Answer me, my prince."

"Yes," Dimitri admits, letting the word come out in a huff. Byleth releases him and he slumps, allowing Byleth to catch him by the hips, holding him firm. "It took a while getting here… without anyone noticing…"

"I can imagine it would have been difficult in those shoes of yours," Byleth comments. Dimitri turns his face away in shame, but Byleth tucks a finger beneath his chin and forces their gazes to meet once more. "It was a jest, love. I think the dress looks magnificent on you."

Dimitri's lips part in a soundless moan. Byleth knows he has always been weak for praise.

"Really?" he whispers, uncertain. Tears glisten in his eyes and Byleth kisses at his lids, willing them away. The ticklish gesture, fortunately, is enough to elicit a giggle, and Byleth pulls back to appreciate his newly formed smile.

"Well," Byleth says, "I cannot so much as consider a moment when you have been  _ unattractive.  _ This, however…," he mutters, appreciatively running his hands over Dimitri's sides, "is especially tantalizing. And as much as I love this dress, I want nothing more than to ruin it."

Dimiri says nothing. Byleth's lips curl into a smirk.

"Will you allow me to?"

Dimitri squirms under Byleth's close scrutiny. When he answers, his tone is soft, shy.

"Please."

***

Byleth's chamber is dark save for the lone lamp shining a dim circle of light at his bedside. He appreciates the way it plays over Dimitri's face, molten orange and warm, emphasizing both the strong bones of his cheeks and the sharp line of his jaw. His eyes, normally a soothing, familiar blue, are tinted red in an oddly beautiful but ominous way.

_ Like a painting come alive,  _ is Byleth's first thought as he drinks in the sight, which he finds so ridiculous he cannot help the small chuckle that escapes his lips. He is quick to stifle it, regardless, as he sits on the edge of the bed and places a hand on Dimitri's ankle, still concealed by his gloves.

"Darling," he says, slowly, letting his words fill the silence, "I am unable to promise that I will be gentle with you tonight. Do you understand?"

Dimitri, laid out on the mattress in an (albeit unintentionally) salacious manner, manages a nod. Byleth smiles and reaches for his right heel, tugging it off his foot. Dimitri's breath catches in response.

"If I should hurt you," Byleth continues, "you need only say the word, and I will cease instantly. Do you understand this, as well?"

Another nod, but it is not satisfactory. Byleth craves a verbal response. "Use your words, love."

"Yes," Dimitri says, between heavy breaths. His anticipation is clear as day, evident in the way he clutches the sheets so hard his knuckles turn white. He inhales sharply as Byleth removes his other heel. "I understand. Please, Byleth."

"Patience." The bed creaks as Byleth crawls upon it, planting his legs at either of Dimitri's sides and gazing down upon him with a contemplative expression. His thoughts flood with ideas for what he should do to Dimitri first, and what expression he would most like to see on Dimitri's face by the time he's finished.

He traces a thumb along Dimitri's bottom lip. Dimitri shudders but catches his wrist, holding him in place. "You are not making this any easier for me," Byleth tells him.

Dimitri smiles coyly, and he answers, "I should hope not."

Something within Byleth snaps, then. He pulls his hand away and elects instead to tangle his fingers in Dimitri's hair, yanking his head back. His neck now thoroughly exposed, Byleth seizes the opportunity to press swift kisses along the temporarily unmarked skin.

"You," he whispers, "will address me by my title." His free hand lands on Dimitri's hip, sinking into the soft fabric of the dress. "Do I make myself clear?"

"Yes," Dimitri replies.

"Yes, what?" asks Byleth, patient, lips pressed delicately beneath his ear.

"Yes… Professor."

Byleth smirks, rises and contorts to the side so he can rummage through one of the drawers by his bed. It only takes a moment until he finds what he's searching for.

Turning back towards Dimitri, he tugs at the silk string in his hands and holds it out for his inspection, pleased to see how his face lights up in realization.

It's black, thin, but enough to restrain should Byleth tie it tight enough. His very intention.

He need not say it aloud. Dimitri obeys a wordless command, wrenching his fingers from the sheets and holding his arms above his head, allowing Byleth to tie his wrists together. Byleth does just, tying the silk into a delicate ribbon for good measure and leaning back to examine his work.

_ Perfect. _ He can never get over the sight of Dimitri pliant and ready beneath him, but tonight it is especially arousing. Perhaps, he muses, because of the dress, and how absolutely delectable he looks in it.

"You will not speak unless I give you permission," he says, "but you may cry out as much as you'd like. I encourage it, actually."

Without warning, he hikes up the skirt of the dress and mouths at Dimitri's erection, thinly veiled by the fabric of his undergarments. In any case, he's already needy enough that Byleth feels slickness against his lips.

"Already wet," he comments, and Dimitri releases a ragged moan.

_ "Professor,"  _ he hisses, "pl—"

"I did not give you permission to speak," Byleth interrupts, stern. Dimitri silences instantaneously and he pats his thigh. "Good boy."

The sound Dimitri makes in response is strangled, somewhere between a cry and the words he wishes to say but cannot. Byleth smiles against him, loving how easy it is to make him fall apart.

_ I'm the only one who can make him feel this way.  _ Something low stirs in his gut at that thought, something like pride or possessiveness—or perhaps a bit of both.

He sighs. "It's a shame," he whispers.

Dimitri doesn't respond, but the way he tenses shows that he's awaiting an elaboration. Pulling his undergarments down just enough to expose his weeping cock, Byleth continues, "You should have worn panties for me."

"You—  _ Ah!"  _ Dimitri cries, back arching off the bed as Byleth's thumb presses against his tip, traces the head of his erection. He huffs once, twice, arms straining from where they're tied above his head.

"Disobedient," Byleth says, giving him a long, slow stroke, dark leather dragging over skin. He enjoys how Dimitri's face contorts in pleasure. "What am I going to do with you?"

Dimitri's eyes are wide, wild, as Byleth meets his gaze. Byleth hums and places his free palm on Dimitri's cheek. "I could gag you? That would certainly keep you quiet."

He feels Dimitri watching him as he lowers his head, voice low but firm.

"Ah, but that would be a waste, wouldn't it? I wouldn't be able to hear those sweet sounds of yours."

He doesn't allow Dimitri the chance to process that statement. He parts his lips and takes in the head of Dimitri's cock, tongue laving over the head. He regards Dimitri through heavy-hooded eyes, observes his absolutely wrecked appearance.

He sinks lower, deeper, one hand at the base and the other placed on Dimitri's hip to hold him steady as he takes in as much as he can. Dimitri watches him all the while, his breaths heavy, labored.

He wants to touch him.

Byleth knows this well, has done  _ this  _ enough times to know when Dimitri is teetering on the edge of impatience. He can sense it in the way Dimitri thrusts his hips upward for  _ more,  _ can see how Dimitri's fingers sink into the palms of his hands.

It would not be difficult to break the silk binding his wrists. Byleth is aware of this, of Dimitri's brutal strength—and yet he does not rip his binds, or beg for more despite Byleth's orders. He knows that being good will grant him the most reward.

At the thought, Byleth moans around Dimitri's girth. How badly he wishes to reward him… but not yet. He refuses to end their game quite so quickly.

Dimitri's thrusts grow more frantic as he approaches the edge, but Byleth doesn't allow him the opportunity. He pulls off his cock and wipes his mouth with the back of one hand, his own arousal firm beneath his constricting clothing.

He brings his forefinger beneath Dimitri's chin, tilting his chin up. "Tell me," he says, "what do you want?"

"Professor," he pants, and Byleth would be  _ damned  _ if he ever tired of hearing that word from those lips, rough and chapped as they are.  _ "Please, _ Professor."

"Please what?" Byleth asks, but the smile on his face is knowing. "You'll need to be more specific, my love." His hand once more returns to Dimitri's cock. Enough to pleasure, but not finish.

Dimitri's cheeks puff with air, then release. "P-please… Fuck me. Professor. Fuck me, please."

"Such vulgar language for a prince," Byleth says, though his voice breaks pending his excitement. "What would the others say if they saw you like this?"

Dimitri's lashes flutter shut. It takes a moment for him to collect himself. "P-Professor, you are surely… You are  _ torturing  _ me, please!"

"Hm." Byleth lists his head, presses a light kiss against Dimitri's cheek. "I was hoping we could continue this way for a bit longer, but how am I to deny you when you beg so prettily?"

Byleth pulls his pants down low enough to expose his cock, not missing how Dimitri shudders at the sight. He gives himself a loose stroke, curses under his breath. He can't imagine he'll last very long in this state.

"I recall warning you," he mutters, grabbing Dimitri's legs and spreading them apart, "that it was my every intention to make a mess of your dress. I do not plan on going back now."

A shocked sound catches in Dimitri's throat as Byleth's cock prods at his inner thigh, wet and strained and  _ wanting,  _ and despite his half-hearted attempts to keep some semblance of composure, Byleth feels heat rising to his face. He bends, teeth catching Dimitri's earlob, nibbling gently. He plants his hands on either side of Dimitri's head.

"Clench," he commands, and groans as Dimitri does just, legs winding around Byleth's waist and trapping his desire. "Good boy," he whispers, kissing his ear. "My perfect prince."

"Professor," Dimitri says, then clamps his mouth shut. Speaking without permission.

Byleth does not mind. "You may say… only that. Cry it as loud as you'd like, but you may not use any other words. Do you understand?"

"Yes," Dimitri replies. "Professor."

"Good boy," he repeats. Fingers lightly tug at Dimitri's hair as he thrusts his hips forward, causing his cock to plunge between Dimitri's thighs over and over again, ruthless but steady in its pace. Byleth gasps against Dimitri in desperation, speeding up now, aiming to draw more noises from him. For the third time, he finds a firm grip on Dimitri's cock and strokes him on par with his thrusts.

Dimitri is as worked up as he is. As expected, he comes apart swiftly, legs tightening around Byleth's waist and crying out his title like a mantra, tears streaming thin lines down his face. Byleth kisses them away.

"Professor," he says. "Professor…  _ Professor!" _

He cums, staining the dress with his seed, and Byleth means to mimic him. His lips crash against Dimitri's and he finishes with a few final short, sporadic thrusts, spilling alongside Dimitri and slowly rising to examine his work.

He huffs out a laugh. "You may… need to wash the dress."

A smile curls at Dimitri's lips, as well, and they spend the next several minutes regaining their breaths. Byleth unties the silk at Dimitri's wrists and rolls over onto his side to tug Dimitri snug against him, running his hands down his sleeves.

Once they've both settled down, Dimitri groans. "Please do not tell me you intend to make me wear this again."

Byleth hums, pretending to consider the matter. "I'm not certain… Though perhaps you should leave the dress here after you wash it tomorrow, so that we may use it again should the mood strike."

"You cannot be serious, Professor."

Byleth smirks and kisses his cheek. "On the contrary, I have never been  _ more  _ serious."

Dimitri does not answer, though Byleth can guess what he is thinking.  _ You are too much for me. _

"However, if you do desire this to be your last night wearing the dress—"

Byleth flips Dimitri and hovers over him again, grabbing his hand to press gentle kisses over his knuckles. He stares down upon Dimitri bearing renewed desire.

"—please allow me to ruin it just a bit more."

**Author's Note:**

> feel free to talk to me on [twitter!!](https://twitter.com/catboybelphie) i thirst over dimitri a lot more there lmao


End file.
